Cellulose-ether solvent and composition



Patented May 20, i924.

UNlTED STATES EDWARD S. FARROW,

COMPANY, OF

I meant harem @FFHQE.

JR, OF ROCHESTER, NEW YORK, ASSIGNOR IO EASTMAN KODAK ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

CELLULOSE-ETHER SOLVENT AND COMPOSKTIUN'.

Ho Drawing. Application filed Fuly 7,

To all whom it may concern:

Be it known that I, EDWARD S. Fannow, Jr., a citizen of the United States of America, residin at Rochester, in the county of Monroe an State of New York, have invented certain new and useful Improvements in Cellulose-Ether Solvents and Compositions, of which the following is a full, clear, and exact specification.

This invention relates to solvents for making strong fiowable solutions of cellulose ether and also relates to the cellulose ether compositions produced by the aid of such solvents. One object of my invention is to 35 provide a solvent which will dissolve large proportions of cellulose ethers and at the same time yield solutions having a regulated viscosity for use in plastic and film making arts. Another object of my invention is 20 to provide a cellulose ether solution, which has a regulated viscosity, for making strong, flexible, transparent film on the machines and by the methods known in the art.

In U. S. Patent No. 1,188,376, Lilien- 25 fold, June 20, 1916, there are disclosed a series of alkyl ethers of cellulose. Certain of these are practically insoluble in water, and my invention is particularly applicable to ethers having that property, although not limited to them. Such ethers form strong and useful solutions in mixtures of methyl acetate and methyl alcohol. Nevertheless it is sometimes desirable to reduce the viscosity of such solutions, in order to regulate them for film manufacture, without substantially diluting them.

I have discovered that such regulation of the viscosity may be effected by adding small amounts of benzyl acetone to the mixture of methyl acetate and methyl alcohol. Benzyl acetone by itself does not have as much solvent action on cellulose ether as a mixture of methyl alcohol and methyl acetate. The addition of small amounts of it to such mixture would not, therefore, be expected to have a lowering eilect on the viscosity of the resulting solution of cellulose ether. But an amount of benzyl acetone equal to one-seventieth of the wei ht of the methyl acetate and methyl alco 01 3922. Serial No. 573,487.

mixture, for example, will lower the viscosity of a thick solution of cellulose ether in such mixture by about to per cent. This surprising action indicates that, the benzyl acetone has a strong latent solvent power which is made active under these circumstances.

The proportions may vary considerably, but I find that a solution containing 1 part by weight of benzyl acetone to 70 parts of W the mixture of methyl acetate and methyl alcohol is particularly useful, yet any dilution of the solution is negligible. The mixture of the acetate and alcohol may vary also, but I prefer to use the ratio of 90 parts by weight of the former to 10 parts by weight of the latter.

The amount of cellulose ether dissolved in the complete viscosity-regulating solvent may, of course, be considerably varied. By Way of example, I may dissolve 1 part of water-insoluble ethyl cellulose in from 3 to 6 parts of the mixed solvent.

It will be noted that some of the benzyl acetone remains in the finished film formed by flowing or depositing such dopes in the usual way. ()ther substances which impart additional suppleness or incombustibility, or other qualities to the film may be added to the above solutions or dopes, such modifying agents being, for instance, triphen l or trlcresyl phosphate, camphor, monoc lornaphthalene, etc. a

The ingredients are of the ordinary commercial t pe sufliciently purified for the 5: process 0% film manufacture, so as to give dopes yielding films having the proper relative freedom from color.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A composition of matter comprising cellulose ether dissolved in a mixture of methyl alcohol, methyl acetate and benzyl acetone. 95

2. A fiowable film-forming composition comprising an alkyl ether of cellulose dissolved in a mixture of methyl alcohol, methyl acetate and benzyl acetone, the

weight of the latter being approximately 10c one-seventieth the combined Weightsof the film comprising cellulose ether and benzyl methyl acetate and methyl alcohol. acetone. 10 3. A composition of matter comprising a 5. As an article of manufacture, a flowed, solution of 1 part by weight of Water-inflexible, transparent film comprising water- 5 soluble ethyl cellulose in from 3 to 6 parts insoluble ethyl cellulose and benzyl acetone. of a mixture of methyl alcohol, methyl Signed at Rochester, New York, this 30th acetate and benzyl acetone. day of June, 1922.

4. As an article of manufacture, a flexible EDWARD S. FARROW, JR. 

